Delta Clipper redux

[tomnackid]

Why did the developers of the Delta Clipper (DC-X, DC-Y--or Hudson's Phoenix for that matter) put all of their eggs in the single stage to orbit (SSTO) basket? What's to stop a VTOL spacecraft from having 2 stages? SSTO's are notoriously sensitive to tiny changes in weight--a few pounds over the design weight can make the entire system unworkable. Changing to a multi stage design would make the development of a VTOL spacecraft much easier. The first stage could be a standard throwaway booster with the second stage being the Delta Clipper (option 1) or both stages can be VTOL (option 2).<br /><br />The only disadvantage over the SSTO Clipper is that you will need area downrange to dump the booster for option 1 or a landing pad for option 2.

 

[larper]

Agreed. There is no need for DC-X to be single stage. It is a good goal in the long run if you can make single stage cheaper and as reliable as two stage. But first cut, go for two stage. <br /><br />Of course, for simplicity sake, make the first stage as similar to the second as possible. Make production, maintenance, and training simpler. So, a DC-X1/DC-X2 stack would be ideal.<br /><br />It wasn't DC-X that demanded SSTO. DC-X was a test bed for the reusable part. It was X33 that demanded SSTO. The DC-X derived proposal was in my mind the best solution.<br /><br />The one thing I always liked about DC-X was that it could be envisioned to be self-ferrying. So, yes, your first stage DC-X ends up down range. It refuels and flys itself back to base. This is one of the HUGE advantages to VTVL. (or HTHL, but I hate HTHL with current technology. We won't have HTHL for many decades, if ever.) <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>

 

[nacnud]

For a interesting description of a TSTO VTVL reusable launcher try and find a copy of The Rocket Company, which describes the fictional development of such a vehicle.

 

[gunsandrockets]

"What's to stop a VTOL spacecraft from having 2 stages? "<br /><br />Another possibility is a 1-1/2 stage vehicle. True drop tanks (unlike the structural Space Shuttle external tank) could greatly benefit the design of a Delta Clipper type RLV. The payload mass margin to orbit could be greatly improved plus the reentry mass (and associated thermal protection system mass) could be reduced.<br /><br />I believe the desire for SSTO was to simplify and improve flight serviceing and turnaround. A SSTO RLV which does not shed any parts and which returns directly to it's launch point makes flight operations tremendously simpler. The downside is it's damn hard to make SSTO work within the existing limits of rocket engines, structural materiel and thermal protection.